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However, welcome back to my blog.
Pressing the power button of a computer system causes the computer to come up and the word denoted for such action is booting, We really need to know what is happening behind the screen once the power button is pressed which I will write on today.
Therefore, let's see what happens behind the screen.
Boot is coined from bootstrap which means to put on, therefore, booting is the process of transferring copies of operating system from secondary memory into the primary memory. Before now, starting up a computer goes with typing commands before the operating system comes up but the modern operating system and applications stores data and program code on secondary memory where the CPU only works on data on the Primary memory which is the working environment of the Operating system.
That brings us to;
During booting, sequence of loading is transpiring, the process order in searching for program code in secondary memory to load in the operating system (OS) by the computer is detailed below
designed using pixel lab
Hence, explaining the process order;
POWER-UP
This is the only process that is initiated by the computer user, whereby the user supplies power from the external source to the internal hardware of the computer and when the power gets to the CPU, the program code and data in the ROM is executed, the ROM contains specific code which is executed immediately the power-up. Both CPU and ROM are located at the motherboard, the motherboard functions as the direct interface between the computer's internal hardware and the external power supply, hence pressing the power-up button boot-up process is outrightly initiated.
POWER-ON SELF TEST
In this stage, self test are carried out on the various boot-device required for the system to start up, they are done on Ram, ROM and any other hardware attached for proper functioning.
FINDING BOOT DEVICE
Once the the power-on self test has been done and all are functioning properly a search process is carried on the boot-devices for their unit BIOS( basic Input and output system) mostly this is found on windows Os. BIOS functions fundamentally as the getting -to -know process of making sure that the hardware communicates with the motherboard and provides all the information needed to ensure that it can receive and transfer messages to the motherboard itself and other connected hardware. Once the BIOS has gotten to know that their is communication between the peripheral and motherboard then the BIOS can be said to be configured. Then comes the next order;
LOADING THE OPERATING SYSTEM
The operating system can said to be a software that acts as an intermediary between the hardware and user because OS is a software and software is a set of instructions that tells the computer the task to perform. Therefore, without loading the Operating system there will be no task to perform which means no need for booting. Here, when loading operating system the BIOS which is already configured transfers some copies of the OS into primary memory from where it is stored secondary memory. Once the operating system has been loaded then comes the final stage;
TRANSFER CONTROL
Here, the full control of the machine is transferred to the operating system as part of the final stage of the boot process. At this point, the operating system begins to launch any specific applications which the user has already installed that relies on it to function successfully.
Once the applications which are already customized by the user is targeted by the operating system launch, the computer is fully booted then the user can interact with the computer.
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